Vehicle for an automated storage and retrieval system

ABSTRACT

The invention concerns an automated storage and retrieval system, a storage container handling vehicle and a method for operating such a system. The system comprises a plurality of vehicles, where each vehicle comprises a vehicle body ( 30 ), a thereto connected wheel assembly configured to guide the vehicle along the track system, a container picking device ( 4 ) for releasably attaching to a storage container, comprising one or more pivot arms ( 5 ) having a first end pivotally connected to the vehicle body at pivot point (PP). The configuration of the container picking device is such that it is movable in a pivoting motion of the pivot arm about the pivot point between a first, lifting position enabling the container picking device to lift at least one storage container from a position outside the horizontal extent of the vehicle body and a second, transport position enabling the container picking device to hold the at least one storage container at least partly inside the horizontal extent of the vehicle body.

TECHNICAL FIELD

The present invention relates to an automated storage and retrievalsystem, a vehicle for lifting and moving storage containers stacked instacks within the system and a method thereof.

BACKGROUND AND PRIOR ART

FIG. 1 discloses a typical prior art automated storage and retrievalsystem 1 with a framework structure 100 and FIG. 2 discloses a prior artcontainer handling vehicle 101 of such a system 1.

The framework structure 100 comprises a plurality of upright members 102and a plurality of horizontal members 103 which are supported by theupright members 102. The members 102, 103 may typically be made ofmetal, e.g. extruded aluminum profiles.

The framework structure 100 defines a storage grid 104 comprisingstorage columns 105 arranged in rows, in which storage columns 105storage containers 106, also known as bins, are stacked one on top ofanother to form stacks 107. Each storage container 106 may typicallyhold a plurality of product items (not shown), and the product itemswithin a storage container 106 may be identical, or may be of differentproduct types depending on the application. The storage grid 104 guardsagainst horizontal movement of the stacks 107 of storage containers 106,and guides vertical movement of the containers 106, but does normallynot otherwise support the storage containers 106 when stacked.

The horizontal members 103 comprise a rail system 108 arranged in a gridpattern across the top of the storage columns 105, on which rail system108 a plurality of container handling vehicles 101 are operated to raisestorage containers 106 from and lower storage containers 106 into thestorage columns 105, and also to transport the storage containers 106above the storage columns 105. The rail system 108 comprises a first setof parallel rails 110 arranged to guide movement of the containerhandling vehicles 101 in a first direction X across the top of the framestructure 100, and a second set of parallel rails 111 arrangedperpendicular to the first set of rails 110 to guide movement of thecontainer handling vehicles 101 in a second direction Y, which isperpendicular to the first direction X. In this way, the rail system 108defines grid columns 112 above which the container handling vehicles 101can move laterally above the storage columns 105, i.e. in a plane whichis parallel to the horizontal X-Y plane.

Each container handling vehicle 101 comprises a vehicle body 101 a, andfirst and second sets of wheels 101 b, 101 c which enable the lateralmovement of the container handling vehicle 101 in the X direction and inthe Y direction, respectively. In FIG. 2 two wheels in each set arevisible. The first set of wheels 101 b is arranged to engage with twoadjacent rails of the first set 110 of rails, and the second set ofwheels 101 c is arranged to engage with two adjacent rails of the secondset 111 of rails. Each set of wheels 101 b, 101 c can be lifted andlowered, so that the first set of wheels 101 b and/or the second set ofwheels 101 c can be engaged with the respective set of rails 110, 111 atany one time.

Each container handling vehicle 101 also comprises a lifting device (notshown) for vertical transportation of storage containers 106, e.g.raising a storage container 106 from and lowering a storage container106 into a storage column 105. The lifting device comprises a grippingdevice (not shown) which is adapted to engage a storage container 106,and which gripping device can be lowered from the vehicle body 101 a sothat the position of the gripping device with respect to the vehiclebody 101 a can be adjusted in a third direction Z which is orthogonalthe first direction X and the second direction Y.

Conventionally, and also for the purpose of this application, Z=1identifies the uppermost layer of the grid 104, i.e. the layerimmediately below the rail system 108, Z=2 the second layer below therail system 108, Z=3 the third layer etc. In the embodiment disclosed inFIG. 1, Z=8 identifies the lowermost, bottom layer of the grid 104.Consequently, as an example, and using the Cartesian coordinate systemX, Y, Z indicated in FIG. 1, the storage container identified as 106′ inFIG. 1 can be said to occupy grid location or cell X=10, Y=2, Z=3. Thecontainer handling vehicles 101 can be said to travel in layer Z=0 andeach grid column 112 can be identified by its X and Y coordinates.

Each container handling vehicle 101 comprises a storage compartment orspace for receiving and stowing a storage container 106 whentransporting the storage container 106 across the grid 104. The storagespace may comprise a cavity arranged centrally within the vehicle body101 a, e.g. as is described in WO2014/090684A1, the contents of whichare incorporated herein by reference.

Alternatively, the container handling vehicles 101 may have a cantileverconstruction, as is described in NO317366, the contents of which arealso incorporated herein by reference.

The container handling vehicles 101 may have a footprint, i.e. anextension in the X and Y directions, which is generally equal to thelateral or horizontal extension of a grid column 112, i.e. the extensionof a grid column 112 in the X and Y directions, e.g. as is described inWO2015/193278A1, the contents of which are incorporated herein byreference.

Alternatively, the container handling vehicles 101 may have a footprintwhich is larger than the lateral extension of a grid column 112, e.g. asis disclosed in WO2014/090684A1.

The rail system 108 may be a single rail system, as is shown in FIG. 3.

Alternatively, the rail system 108 may be a double rail system, as isshown in FIG. 4, thus allowing a container handling vehicle 101 having afootprint generally corresponding to the lateral extension of a gridcolumn 112 to travel along a row of grid columns even if anothercontainer handling vehicle 101 is positioned above a grid columnneighboring that row. Both the single and double rail system forms agrid pattern in the horizontal plane P comprising a plurality ofrectangular and uniform grid locations or grid cells 122, where eachgrid cell 122 comprises a grid opening 115 being delimited by a pair oftracks 110 a,110 b of the first tracks 110 and a pair of tracks 111a,111 b of the second set of tracks 111. In FIG. 4 the grid cell 122 isindicated by a dashed box.

Each grid cell 122 has a width which is typically within the interval of30 to 150 cm, and a length which is typically within the interval of 50to 200 cm. Each grid opening 115 has a width and a length which istypically 2 to 10 cm less than the width and the length of the grid cell122.

In a storage grid 104, a majority of the grid columns 112 are storagecolumns 105, i.e. grid columns 105 where storage containers 106 arestored in stacks 107. However, a grid 104 normally has at least one gridcolumn 112 which is used not for storing storage containers 106, butwhich comprises a location where the container handling vehicles 101 candrop off and/or pick up storage containers 106 so that they can betransported to an access station 32 (see FIGS. 12-14) where the storagecontainers 106 can be accessed from outside of the grid 104 ortransferred out of or into the grid 104. Within the art, such a locationis normally referred to as a “port” and the grid column 112 in which theport is located may be referred to as a port column 19,20.

The grid 104 in FIG. 1 comprises two port columns 19 and 20. The firstport column 19 may for example be a dedicated drop-off port column wherethe container handling vehicles 101 can drop off storage containers tobe transported to an access or a transfer station (23), and the secondport column 20 may be a dedicated pick-up port column where thecontainer handling vehicles 101 can pick up storage containers 106 thathave been transported to the grid 104 from an access or a transferstation 32.

The access station 32 may typically be a picking or a stocking stationwhere product items are removed from or positioned into the storagecontainers 106. In a picking or a stocking station 32, the storagecontainers 106 are normally never removed from the automated storage andretrieval system 1, but are returned into the grid 104 once accessed. Aport can also be used for transferring storage containers out of or intothe grid 104, e.g. for transferring storage containers 106 to anotherstorage facility (e.g. to another grid or to another automated storageand retrieval system), to a transport vehicle (e.g. a train or a lorry),or to a production facility.

A conveyor system comprising conveyors is normally employed to transportthe storage containers between the ports 19,20 and the access station32.

If the port and the access station 32 are located at different levels,the conveyor system may comprise a lift device for transporting thestorage containers 106 vertically between the port 19,21 and the accessstation 32.

The conveyor system may be arranged to transfer storage containers 106between different grids, e.g. as is described in WO2014/075937A1, thecontents of which are incorporated herein by reference.

WO2016/198467A1, the contents of which are incorporated herein byreference, disclose an example of a prior art access system havingconveyor belts (FIGS. 5a and 5b ) and a frame mounted track (FIGS. 6aand 6b ) for transporting storage containers between ports and workstations where operators can access the storage containers.

When a storage container 106 stored in the grid 104 disclosed in FIG. 1is to be accessed, one of the container handling vehicles 101 isinstructed to retrieve the target storage container 106 from itsposition in the grid 104 and transport it to the drop-off port 19. Thisoperation involves moving the container handling vehicle 101 to a gridlocation above the storage column 105 in which the target storagecontainer 106 is positioned, retrieving the storage container 106 fromthe storage column 105 using the container handling vehicle's 101lifting device (not shown), and transporting the storage container 106to the drop-off port 19. If the target storage container 106 is locateddeep within a stack 107, i.e. with one or a plurality of other storagecontainers 106 positioned above the target storage container 106, theoperation also involves temporarily moving the above-positioned storagecontainers prior to lifting the target storage container 106 from thestorage column 105. This step, which is sometimes referred to as“digging” within the art, may be performed with the same containerhandling vehicle that is subsequently used for transporting the targetstorage container to the drop-off port 19, or with one or a plurality ofother cooperating container handling vehicles. Alternatively, or inaddition, the automated storage and retrieval system 1 may havecontainer handling vehicles specifically dedicated to the task oftemporarily removing storage containers from a storage column 105. Oncethe target storage container 106 has been removed from the storagecolumn 105, the temporarily removed storage containers can berepositioned into the original storage column 105. However, the removedstorage containers may alternatively be relocated to other storagecolumns.

When a storage container 106 is to be stored in the grid 104, one of thecontainer handling vehicles 101 is instructed to pick up the storagecontainer 106 from the pick-up port 20 and transport it to a gridlocation above the storage column 105 where it is to be stored. Afterany storage containers positioned at or above the target position withinthe storage column stack 107 have been removed, the container handlingvehicle 101 positions the storage container 106 at the desired position.The removed storage containers may then be lowered back into the storagecolumn 105, or relocated to other storage columns.

For monitoring and controlling the automated storage and retrievalsystem 1, e.g. monitoring and controlling the location of respectivestorage containers 106 within the grid 104; the content of each storagecontainer 106; and the movement of the container handling vehicles 101so that a desired storage container 106 can be delivered to the desiredlocation at the desired time without the container handling vehicles 101colliding with each other, the automated storage and retrieval system 1comprises a control system which typically is computerized and whichtypically comprises a database for keeping track of the storagecontainers 106.

A problem associated with known automated storage and retrieval systems1 is that the area surrounding the ports 19,20 may become congested withcontainer handling vehicles 101 instructed to drop off or pick upstorage containers 106. This may seriously impede the operation of theautomated storage and retrieval system 1. In small systems, thissituation may possibly be alleviated by adding ports to the grid, asthis will allow the container handling vehicles 101 to be distributedamong a larger number of ports in order to avoid congestion. However, ifports are added, the conveyor system infrastructure must normally beincreased. This requires space, which may not necessarily be available.Also, adding conveyor system infrastructure is costly.

Furthermore, the current trend within the automated storage andretrieval system industry is that there is an increasing demand forlarger storage grids. Since the number of storage containers stored in agrid generally scales as the volume of the grid, but the space availablefor ports generally scales as the surface of the grid, increasing thenumber of ports will not necessarily solve the congestion problem whenthe grid size increases.

Another problem with prior art automated storage and retrieval systemsusing storage container vehicles with single cell design is that thesevehicles necessitates a container receiving cavity within the vehiclebody itself and which must be open towards the underlying grid. Strictspace constrains are therefore set as to the locations and sizes ofnecessary vehicle components, e.g. lifting devices and wheeldisplacement means. In order to maximize the horizontal cross section ofthe cavity, the prior art single cell vehicles arrange at least some ofthe vehicle components above the cavity (see e.g. WO 2015/193278 A1)and/or within the wheels (see e.g. WO 2016/120075 A1), a solution thatresults in high complexity and cost.

In addition, the single cell vehicles may handle only one container ineach operation, thereby setting a limitation of the rate containers maybe handled in operating the above mentioned storage and retrievalsystem.

In view of the above, it is desirable to provide an automated storageand retrieval system, and a method for operating such a system, thatsolve or at least mitigate one or more of the aforementioned problemrelated to use of prior art storage and retrieval systems.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the main claims,while the dependent claims describe other characteristics of theinvention.

In particular, the invention concerns an automated storage and retrievalsystem comprising a track system comprising a first set of paralleltracks arranged in a horizontal plane (P) and extending in a firstdirection (X) and a second set of parallel tracks arranged in thehorizontal plane (P) and extending in a second direction (Y) which isorthogonal to the first direction (X). As a result, the first and secondsets of tracks form a grid pattern in the horizontal plane (P)comprising a plurality of adjacent grid cells, each comprising a gridopening defined by a pair of neighboring tracks of the first set oftracks and a pair of neighboring tracks of the second set of tracks. Thesystem further comprises a plurality of stacks of storage containersarranged in storage columns located beneath the track system, verticallybelow the grid openings and a vehicle, preferably a plurality ofvehicles, for lifting and moving storage containers stacked in thestacks. Each vehicle comprises a vehicle body, a thereto connected wheelassembly configured to guide the vehicle along the track system eitherin the first direction (X), in the second direction (Y) or in both, acontainer picking device for releasably attaching to a storagecontainer. The container picking device further comprises one or morearms, preferably pivot arms comprising a first end pivotally connectedto the vehicle body at a fixed or movable pivot point (PP) and a second,distal end. The configuration of the container picking device is suchthat it is movable in a pivoting motion of the pivot arm about the pivotpoint between a first, lifting position enabling the container pickingdevice to lift at least one storage container from a position beyond thehorizontal extent of the vehicle body and a second, transport positionenabling the container picking device to hold the at least one storagecontainer at least partly within the horizontal extent of the vehiclebody, above the vehicle body. ‘Horizontal extend’ is herein defined asthe outermost horizontal boundaries of the vehicle body. Further,‘vehicle body’ is herein defined as any common connection point for thewheel assembly and the container picking device, and may include anyopen frames, protective box, etc. The arms, for example in form of pivotarms in respective pivot points, may be directly or indirectly connectedto said vehicle body.

The pivot arm, or pivot arms, may rotate around an axis perpendicular tothe horizontal plane (P), for example a pivot arm revolving around avertical axis at the periphery of the vehicle body. However, in anadvantageous configuration the container picking device is configuredsuch that the pivotal movement of the pivot arm is restricted to avertical plane oriented in the first direction (X).

The container picking device preferably comprises an attachment devicepivotally connected to the pivot arm and configured to allow releasableattachment to the at least one storage container. Such an attachmentdevice may further comprise an attachment body pivotally connected tothe pivot arm and a gripping device/engagement device connected to theattachment body, for releasably gripping/engaging the at least onestorage container. The maximum horizontal extent of the attachmentdevice should preferably cover at least the horizontal extent of astorage container to be picked in order to create a high stability inthe picking process. If several containers should be picked in a singlepicking operation, the horizontal extent should preferably at leastcover the number of containers to be picked. High stability refers tothe stability of the withdrawal of the container from the storagecolumn. By ensuring that the attachment device has a horizontal extentthat is equal to the horizontal extent of the container, the liftingunit be operated on or near the horizontal boundaries of the container.

In order to further increase the stability of the picking operation thecontainer picking device preferably comprises a first pivot armpivotally connected to a first side of the vehicle body aligned in thefirst direction (X), for example a first side wall, and a second pivotarm pivotally connected to a second side of the vehicle body aligned inthe first direction (X), for example a second side wall. In thisexemplary configuration, the first and second pivot arms mayadvantageously be pivotally connected to respective side walls of theattachment body aligned in the first direction (X). The higher stabilityis achieved inter alia since the above disclosed arrangement of thepivot arms prevent undesired twisting during operation.

The container picking device may further comprise two mutually parallelfirst pivot arms pivotally connected to a first side wall of the vehiclebody aligned in the first direction (X). Further, two mutually parallelsecond pivot arms may be pivotally connected to a second side wall ofthe vehicle body aligned in the first direction (X). Theseconfigurations increase further the stability of the lifting operationi.a. since the mutually parallel pivot arms ensures that the liftingunit remains horizontal.

In one embodiment of the invention, each vehicle has a footprint, atleast in one direction, that is equal to, or less than, the horizontalextent of a grid cell of the underlying track system. With thisembodiment the vehicle may pass each other on neighboring cells on eachlateral/horizontal side of the vehicle body when the pivot arm(s) is/arein the transport position resulting in a horizontal extent of thecontainer picking device which do not go beyond the horizontal extent ofthe vehicle body.

In an alternative embodiment of the invention, each vehicle has afootprint of the vehicle that is equal to, or near equal to, thehorizontal extension of a grid cell of the underlying track system timesan integer of two or more.

The wheel assembly may include any means capable of moving the vehiclein the desired direction on the track system. However, in a preferredconfiguration the wheel assembly comprises a first set of wheels forengaging with the first set of tracks to guide movement of the vehiclein the first direction (X). For example, the first set of wheels maycomprise four wheels arranged at or near each corner of the vehiclebody, all oriented with their rotational axis in the horizontal plane(P), perpendicular to the first direction (X).

The vehicle body may be divided into a lower part onto which the wheelassembly is rotatably mounted and an upper part located above the wheelassembly (18). In order to ensure free pivoting movements of thecontainer picking device, it may further be advantageous to design theupper part with a continuous or stepwise reduction in horizontal extent,for example with an inclination inwards along the first direction (X)having an inclination angle relative to the horizontal plane (P) thatmay be equal on both side of the vehicle body in the first direction(X). If the wheel assembly comprises four wheels, each wheel mayadvantageously be arranged at or near the corners of the lower part andfurther arranged so that they do not interfere with the pivotal movementof the pivot arms/storage container. Note that the term wheel assemblymay comprise any means ensuring movements of the vehicle, for example aset of belts, a set of wheels being passive, i.e. set in motion byexternal motors, a set of wheels containing one or more hub motors,electronics related to the motors, etc. Any reference to wheels may bereplaced by belts of any kind.

The pivot point (PP) or pivot points (PP) may in an exemplaryconfiguration be located at the lower part of the vehicle body, inbetween two wheels of the first set of wheels.

The pivot arms may be configured with arcuate recesses partlyencapsulating part of the wheels and/or part of the wheel axle duringpivoting in order to allow the pivot arm to be wider. Such recesseswould also allow for the pivot point to be lower down on the vehiclebody while still allowing a suitably long reach when pivoted. Further,the recesses could also act as a brake on the wheel to ensure thevehicle to not to move as the container is lowered.

In another embodiment of the invention the attachment device comprises,in addition to the attachment body pivotally connected to the pivot armand the gripping device/engagement device configured to releasablygrip/engage at least one storage container, a storage container liftmechanism connected to the attachment body. The storage container liftmechanism may in this embodiment be configured to raise and lower the atleast one storage container from a position on or within a grid columnto a position fully above the track system. The gripping device may bearranged on the lower end of the storage container lift mechanism.

In order to provide sufficient torque to the pivot arm or pivot arms,the vehicle body may be equipped with one or more pivot arm motors, oneor more arm shafts, and, if necessary according to the specificconfiguration choice, gearing means to provide torque from the shaft(s)to the pivot arms. The strength of the applied torque should at leastenable lifting of a single void storage container between the pickingposition and the transport position.

In yet another embodiment of the invention the wheel assembly comprisesa first set of wheels for engaging with the first set of tracks to guidemovement of the vehicle in the first direction (X) and a second set ofwheels for engaging with the second set of tracks to guide movement ofthe vehicle in the second direction (Y), wherein the first set of wheelsand/or the second set of wheels is vertically displaceable bydisplacement means arranged within the vehicle body.

The invention also relates to a vehicle suitable for lifting and movingstorage containers stacked in stacks within an automated storage andretrieval system in accordance with the system described above. Thevehicle is configured to move on the track system above the storagecolumns and comprises a vehicle body and a wheel assembly rotatablyconnected to the vehicle body in order to guide the vehicle along thetrack system in the first direction (X), the second direction (Y) orboth directions. The vehicle further comprises a container pickingdevice for releasably attaching to a storage container. The containerpicking device comprises a pivot arm comprising a first end pivotallyconnected to the vehicle body at pivot point (PP) and a second, distalend. The configuration of the container picking device is such that itis movable in a pivoting motion of the pivot arm about the pivot pointbetween a first, lifting position enabling the container picking deviceto lift at least one storage container from a position outside thehorizontal extent of the vehicle body and a second, transport positionenabling the container picking device to hold the at least one storagecontainer at least partly inside the horizontal extent of the vehiclebody.

The invention also relates to a method of operating an automated storageand retrieval system, preferably a system as described above. The systemcomprises a three-dimensional grid comprising a plurality of storagecolumns in which storage containers are stacked one on top of another invertical stacks, and a port zone which comprises at least one port,allowing transfer of storage containers out of and/or into the grid. Thesystem further comprises a plurality of first vehicles which areoperated laterally on the grid for retrieving one or more storagecontainers from, and storing one or more storage containers in, thestorage columns, and for transporting the storage containers laterallyacross the grid. The method according to the invention comprises thesteps of:

-   -   arranging, in the grid, a transfer zone comprising a plurality        of transfer columns for temporarily storing storage containers        when in transit between the storage columns and the at least one        port;    -   utilizing the first vehicles to transport the storage containers        between the storage columns and the transfer columns; and    -   utilizing a plurality of second vehicles which are operated on        the grid to transport the storage containers between the        transfer columns and the at least one port.

For use in the method, each of the plurality of second vehiclescomprises a vehicle body, a wheel assembly connected to the vehicle bodyand configured to guide the second vehicle along the track system in thefirst direction (X) and/or the second direction (Y), a container pickingdevice for releasably attaching to a storage container within thetransfer zone comprising a pivot arm comprising a first end pivotallyconnected to the vehicle body at pivot point (PP) and a second, distalend. The configuration of the container picking device is such that itis movable in a pivoting motion of the pivot arm about the pivot pointbetween a first, lifting position enabling the container picking deviceto lift at least one storage container from a position outside thehorizontal extent of the vehicle body and a second, transport positionenabling the container picking device to hold the at least one storagecontainer at least partly inside the horizontal extent of the vehiclebody.

In the following, numerous specific details are introduced by way ofexample only to provide a thorough understanding of embodiments of theclaimed system, vehicle and method. One skilled in the relevant art,however, will recognize that these embodiments can be practiced withoutone or more of the specific details, or with other components, systems,etc. In other instances, well-known structures or operations are notshown, or are not described in detail, to avoid obscuring aspects of thedisclosed embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

Following drawings are appended to facilitate the understanding of theinvention.

FIG. 1 is a perspective view of a grid of a prior art automated storageand retrieval system.

FIG. 2 is a perspective view of a prior art container handling vehicle.

FIG. 3 is a top view of a prior art single rail grid.

FIG. 4 is a top view of a prior art double rail grid.

FIG. 5 (a) and (b) is a side view and a top view of a vehicle accordingto one embodiment of the invention.

FIG. 6 (a)-(c) are side views of a vehicle according to a secondembodiment of the invention.

FIG. 7 (a)-(c) are side views of a vehicle according to a thirdembodiment of the invention.

FIG. 8 is a side view of a vehicle according to a fourth embodiment ofthe invention.

FIG. 9 is a side view of a vehicle according to a fifth embodiment ofthe invention.

FIG. 10 (a) and (b) are side views of the vehicle of FIG. 6 illustratingschematically two different means for attaching a storage container tothe vehicle.

FIG. 11 is a perspective view of a lifting device capable of lifting aplurality of storage containers in one lifting operation.

FIG. 12 is a top view of grid of an automated storage and retrievalsystem according to one embodiment of the invention.

FIG. 13 is a top view of grid of an automated storage and retrievalsystem according to a second embodiment of the invention.

FIG. 14 is a top view of grid of an automated storage and retrievalsystem according to a third embodiment of the invention.

In the drawings, like reference numerals have been used to indicate likeparts, elements or features unless otherwise explicitly stated orimplicitly understood from the context.

DETAILED DESCRIPTION OF THE INVENTION

In the following, embodiments of the invention will be discussed in moredetail with reference to the appended drawings. It should be understood,however, that the drawings are not intended to limit the invention tothe subject-matter depicted in the drawings.

Particular embodiments of a storage structure of an automated storageand retrieval system 1 are shown in FIGS. 12, 13 and 14 in top views.The storage grid 104 of each storage structure constitutes a framework100 of in total 1800 grid columns 112, where the width and length of theframework corresponds to the width and length of 36 and 50 grid columns112, respectively. The top layer of the framework 100 is a track system108 onto which a plurality of vehicles 3,101 are operated. FIGS. 12 and13 shows two types of vehicles 3,101, indicated by black and light greyrectangles. The black rectangles symbolize exemplary positions ofcontainer handling vehicles 101 intended to transport storage containers106 to and from their respective grid columns 112 within the framework100 (white area), while light grey rectangles symbolize exemplarypositions of port access vehicles 3 (see FIGS. 5-10) intended totransport the picked storage containers 106 between temporary storagepositions within a transfer zone 35 of the framework 100 (dark greyarea) and a port zone 26 containing one or more container ports 19-21(area framed by a dotted circle).

If not otherwise stated, the framework 100 of the automated storage andretrieval system 1 is constructed in accordance with the prior artframework 100 described above in connection with FIGS. 1-4., i.e. aplurality of upright members 102 and a plurality of horizontal members103 which are supported by the upright members 103, and further that thehorizontal members 103 comprise the track system 108 of parallel tracks110,111 in X direction and Y direction arranged across the top ofstorage columns 105/grid columns 112. The horizontal area of a gridcolumn 112, i.e. along the X and Y directions, may be defined by thedistance between adjacent rails 110 and 111, respectively (see alsoFIGS. 3 and 4).

Consequently, the track system 108 allows the container handlingvehicles 101 and the port access vehicles 3 to move horizontally betweendifferent grid locations, where each grid location is associated with agrid column 112. In the embodiments shown in FIGS. 12 and 13 themovement of each port access vehicle 3 is restricted to the X directiononly, while FIG. 14 shows an embodiment where the port access vehicles 3are configured to move both in X direction and in Y direction, hencehaving the same mobility on the track system 108 as the containerhandling vehicle 101.

In FIG. 1 the grid 104 is shown with a height of eight cells. It isunderstood, however, that the grid 104 in principle can be of any size.In particular it is understood that grid 104 can be considerably widerand/or longer than disclosed in

FIGS. 12-14. For example, the grid 104 may have a horizontal extensionof more than 700×700 grid cells. Also, the grid 104 can be considerablydeeper than disclosed in FIG. 1. For example, the grid 104 may be morethan twelve grid cells deep.

The storage container vehicles 101 may be of any type known in the art,e.g. any one of the automated container handling vehicles disclosed inWO2014/090684 A1, in NO317366 or in WO2015/193278A1 (FIG. 2). In theembodiments shown in FIGS. 12-14 storage container vehicles 101 of thetype disclosed in WO2015/193278A1 is assumed, i.e. storage containervehicles 101 displaying a centrally located storage space for receivingand stowing a storage container 106 and for transport horizontallyacross the grid 104, and a footprint, i.e. an extension in the X and Ydirections which is generally equal the horizontal extension of a gridcolumn 112. This particular configuration will allow a storage containervehicle 101 to transport a storage container 106 above a row of gridcolumns 112 even if another storage container vehicle occupies alocation above a grid column neighboring the grid column row along whichthe first storage container vehicle 101 is traveling.

In the embodiments disclosed in FIGS. 12-14, the framework 100 comprisea storage zone 25, two port zones 26 and two transfer or buffer zones35. The size and number of both transfer zones 35 and port zones 26 mayvary according to need. While the size and position of the port zones 26normally are fixed, the size and position of the transfer zones 35 maybe dynamic and set by the software controlling the storage containervehicles 101 and/or the port access vehicles 3. The grid constitutingthe transfer zone 35 is preferably constructed identical to the gridconstituting the storage zone 25. Alternative solutions may of course beenvisaged such as special grid cells within a transfer zone 35 beingonly one cell deep (Z=1) or a transfer zone 35 where the storagecontainers 106 may be placed only on top (Z=0) of the track system 108.

In the example shown in FIG. 12, the framework 100 comprises a storagezone 25 (white area), two port zones 26 (areas enclosed by dottedcircles) and two transfer zones 35. Each port zone 26, which is forexample three grid cells wide in the X direction and two grid cells longin the Y direction, as for the left port zone, or three grid cells widein the X direction and one grid cell long in the Y direction, as for theright port zone, comprises ports 19-21 where storage containers 106 canbe transferred out of or into the framework 100. The left transfer zone35, linked to the left port zone 26, is three grid cells wide in the Xdirection and 41 grid cells long in the Y direction, while the righttransfer zone 35, linked to the right port zone 26, is three grid cellswide and 42 grid cells long. The storage zone 25, which makes up therest of the framework 100, comprises storage columns 105 in whichstorage containers 106 or bins can be stacked one on top of another toform stacks 107.

A second example of an automated storage and retrieval system 1 is shownin FIG. 13. The system 1 is similar to the example shown in FIG. 12, butall columns constituting the ports 19-21 within the port zones 26 aresituated fully outside the 36×50 framework 100. The left and righttransfer zones 35 are slightly longer, 43 grid cells 36 for both.

For the systems 1 shown in both FIG. 12 and FIG. 13, the vehicles 3dedicated for transporting storage containers 106 between the transferzone(s) 35 and the port zone(s) 26 includes a drive system 18 comprisingwheels 18 a enabling movements of the vehicles in the X direction only.

An example of such an one way vehicle 3 is illustrated in FIG. 5, whereFIG. 5(a) is a side view of the vehicle 3 and FIG. 5(b) is a crosssection view of the vehicle 3 through the horizontal plane marked A-A,respectively. As is apparent from FIG. 5(a) the vehicle 3 comprises twopivot arms 5′,5″ having length L, where one longitudinal end 5 a of eachpivot arm 5′,5″ is pivotally attached to each side of a vehicle body 30of the vehicle 3 at pivot points PP, thereby allowing the arms 5′,5″ topivot around the pivot points (double arrow) 7 in a vertical plane alongthe X direction. The length L is herein defined as the length of a pivotarm 5′,5″ from its pivot point PP on the vehicle body 30 to thetermination point at the other longitudinal end 5 b. The pendulummovements 7 may be activated and maintained by use of a pivot arm motor5 c providing the necessary pivoting torque, either directly onto thearms 5′,5″ or via a pivot arm shaft 5 d connected at the pivot points PPof the two pivot arms 5′,5″. It is understood however that any means forcreating a torque on the arms 5,5′ at their pivot points PP, and/or anyforce directed perpendicular to the longitudinal direction of the arms5,5′, may be used to ensure the pendulum movements 7.

Even though two pivot arms 5′,5″ are illustrated in FIG. 5, it should beunderstood that the vehicle 3 can be equipped with only one pivot arm 5′pivotally attached in any location of the vehicle body 30, for examplein the gravitational center point of the vehicle body 30.

The other, distal end 5 b of each pivot arm 5′,5″ is equipped with meansfor picking up storage containers 106. The releasable coupling with thestorage containers 106 may be achieved using the pivot arms 5′,5″ only,e.g. by exerting pressure onto the side of the storage container 106and/or providing the distal ends 5 b with one or more gripping devices13 (clips, hoods, etc). However, in a preferred embodiment, and asillustrated in FIG. 5(a), the distal ends 5 b are pivotally attached toa lifting unit 6, in FIG. 5a depicted in the form of a cuboid havingsaid gripping device(s) 13 arranged beneath, i.e. on the side of thelifting device 6 facing the underlying framework 100.

The port access vehicle 3 in FIG. 5 is illustrated with one set ofwheels 18 a directed in X direction only. Hence, the vehicle 3 may inthis particular example move only in one direction on the framework 100.As will be further explained later with reference to FIGS. 8 and 9, thevehicle 3 may alternatively, or in addition, be equipped with a secondset of wheels 18 b directed in the Y direction.

A possible modification of the example shown in FIG. 5 is to replace thepivot arms 5′,5″ of fixed length L with telescopic pivot arms (notshown), i.e. pivot arms which length may vary between a minimum lengthL_(min) and a maximum length L_(max). One advantage of such a telescopicsolution is that storage containers 106 situated further away from thevehicle body 30 may be picked up by the vehicle 3. Furthermore, atelescopic solution represents one example of a solution which renderspicking of storage containers 106 in both X direction and Y directionpossible. For example, the vehicle 3 may be equipped with a second pairof pivot arms pivotally attached to the vehicle body 30 and directed inthe Y direction. In order to allow one or more storage containers pickedup by the second pair of pivot arms to be arranged in a transportposition, i.e. at least partly above the vehicle body 30, the first pairof pivot arms 5′,5″ can be fully retracted, thereby avoiding anyinterference with the second pair of pivot arms.

If a lifting unit 6 is present, the fully retracted position of thepivot arms 5′,5″could be in a position where the lower face of thelifting device 6 abuts, or almost abuts, the upper face of the vehiclebody 30. In this configuration, the second pair of pivot arms should belong enough to allow arrangement of the at least one storage containerat least partly above the lifting unit 6.

To ensure maximum pivotal movements of the pivot arms 5′,5″ thehorizontal arrangement of the wheels constituting the wheel assembly 18and the horizontal arrangement of the pivot arms 5′,5″ may be such thatthe pivot arms 5,5″ are movable between each wheel and the vehicle body30, as illustrated in FIG. 5(b). This particular arrangement, whichrepresent an addition or an alternative to the configuration withrecesses mentioned above, also ensures better stability of the pivotingoperation due to the guiding effect from both the vehicle body 30 andthe wheels.

FIG. 6(a)-(c) shows a port access vehicle 3 according to a secondembodiment of the invention, where two mutually parallel pivot arms5′,5″ are pivotally attached to each side walls of the vehicle body 30directed in the X direction, thereby achieving higher stability duringstorage container handling. FIG. 6(a) and FIG. 6(c) show the port accessvehicle 3 in a picking position, that is, the position where the pivotarms 5′,5″ have an angle relative to the horizontal plane (P) causingthe picked storage container 106 to be located fully outside thehorizontal extent of the vehicle body 3.

FIG. 6(b) shows the port access vehicle 3 in a transport position, thatis, the position where the pivot arms 5′,5″ have an angle relative tothe horizontal plane (P) causing the picked storage container 106 to belocated at least partly within the horizontal extent of the vehicle body3.

In addition to the two mutually, parallel pivot arms 5′,5″, the designof the vehicle body 30 of the second embodiment vehicle 3 is differentfrom the cuboid form for the first embodiment vehicle 3 shown in FIG. 5.The vehicle body 30 of the second embodiment vehicle 3 may be dividedinto a lower part 30 a and an upper part 30 b, where the lower part 30 ahas a cuboid shape as for the entire vehicle body 30 in FIG. 5 and theupper part 30 b has a wedged rectangular shape where the planes in atleast the Y direction are upwardly inclined towards the center of thevehicle body 30. The upper part may for example provide additional spacefor vehicle components such as motors. The inclination may be of anyform such as linear or curved. A domed profile may also be envisaged.For all embodiments, the maximum height of the vehicle body 30 may be40% of the horizontal length of the underlying storage cell in the Xdirection or in the Y direction.

As for the first embodiment vehicle 3, the pivot arms 5′,5″ may have afixed length L or be telescopic.

FIG. 7 (a)-(c) shows a third embodiment vehicle 3 configured to allowpicking of a plurality of storage containers 106 in the same operation.In the third embodiment this is achieved by attaching the distal ends 5b of the pivot arms 5′,5″ to a multiple container lifting unit 6. FIG. 7shows an example where the lifting unit 6 is configured to lift twoneighboring storage containers 106 in the X direction. However, themultiple container lifting unit 6 may be configured to handle any set ofstorage containers, for example 3×1 storage containers, 3×2 storagecontainers, 2×2 storage containers or 3×3 storage container. One couldalso envisage a reconfigurable lifting unit such as a telescopic and/orfoldable lifting unit capable of for example change the capacity betweena single storage container lifting unit and a 2×1 storage containerlifting unit. Further, the container picking device 4 may may comprisetwo pivoting picking device parts, each having a lifting unit 6. In suchconfiguration one set of pivot arms constituting part of the firstpicking device part pivots one container and the other set of pivot armsconstituting part of the second picking device part pivots anothercontainer. With two pivoting picking device parts the first may pivotforward and the other may pivot backwards, thereby balancing the weightsduring operation of containers. In order to ensure that the pivot armsmove in an equal but opposite direction, it may be advantageous toinstall a coq system at one or more pivot points. Such a cog system maybe installed for all embodiments.

Apart from the lifting unit 6, the third embodiment vehicle 3 shown inFIG. 7 is identical to the second embodiment vehicle 3 shown in FIG. 6.And as in FIG. 6, FIGS. 7(a) and 7(c) shows the vehicle 3 in a pickingposition, while FIG. 7(b) shows the vehicle 3 in a transport position.

The third embodiment vehicle 3 is configured to move on the track system108 in the X direction only. However, as will be described withreference to FIG. 9, the third embodiment vehicle 3 may be configured tomove on the track system 108 in the X direction or the Y direction.

FIGS. 8 and 9 show the above-mentioned configurations of the vehicle 3,but where a second set of wheels 18 b for moving the vehicle 3 in the Ydirection is added to the wheel assembly 18. In order to enable changeof direction between X direction and Y direction one or both of the setsof wheels 18 a,18 b should be made vertically displaceable, for exampleby arranging vertical displacement means within or onto the vehicle body30. The alternative of adding wheels to enable movement in the Ydirection in addition to the wheels for movement in the X direction, maybe implemented for all embodiments shown in FIGS. 5-7.

At least one of the wheels in each set 18 a, 18 b is motorized in orderto propel the vehicle 3 along the track system 108. Advantageously, Atleast one wheel of each or both sets may comprise a hub motor i.e. anelectric motor that is coupled to, or incorporated into, the hub of awheel and drives the wheel directly. An example of a vehicle with such amotor is disclosed in WO2016/120075A1, the contents of which areincorporated herein by reference.

The storage containers 106 may be picked and lowered by the vehicle 3 invarious ways of which two exemplary configurations are shown in FIG. 10.

In FIG. 10 (a) the gripping device/engagement device 13 forgripping/engaging a storage container 106 is shown in form of clipsarranged in or near each of the four corners on the horizontal plane ofthe lifting unit 6 facing the underlying framework 100. The pivot arms5′,5″ pivots until the gripping device 13 is within reach of a dedicatedgripping device structure on or within the storage container 106. Thegripping device 13 then grips the storage container 106, and the pivotarms 5′,5″ pivot back until the vehicle 3 is in a transport position,for example with the pivot arms 5′,5″ directed perpendicular to thehorizontal plane (P).

In FIG. 10 (b) the gripping device 13 for gripping a storage container106 is shown in form of clips arranged under a lifting plate 22suspended at the lifting unit 6 by a storage container lift mechanism16. The lift mechanism 16 may for example be identical to the vehiclelifting device disclosed in WO 2015/193278 A1, the contents of which areincorporated herein by reference, thereby allowing the vehicle 3 tolift/lower storage containers 106 from/to stacks 107 below the tracksystem 108. A lifting motor 40 (FIG. 5) for lowering and raising thelifting plate 22 may be arranged within the lifting unit 6 or within thevehicle body 30, thereby enabling control of the position of the liftingplate 22 with respect to the lifting unit 6 in the third direction Z.

For handling a plurality of storage containers 106, as disclosed abovewith reference to FIG. 7, the gripping device 13 may comprise a numberclips that corresponds to the total number of upper horizontal corner ofthe storage containers 106 to be picked by the vehicle 3 in the samepicking operation. FIG. 11 shows an example of 4×4 clips allowing up tofour storage containers 106 to be picked in the same operation. Each,some or all the clips in each lifting unit 6 may be remotely operated bya control system. In FIG. 11 the gripping device 13 is shown arranged ona lifting plate 22. However, the same or a similar gripping device 13solution with four times the number of storage containers 106 to bepicked may be arranged on the lifting unit 6 as depicted in FIG. 10(a).Each corner of the lower face of the lifting plate 22, or each corner ofthe lower plane of the lifting unit 6, is preferably arranged with oneor more steering pins 17 to ensure adequate guiding of the grippingdevice 13 into the gripping device receiving structure.

FIG. 14 shows a third example of an automated storage and retrievalsystem 1. As for the system 1 in FIG. 12, the port columns 19,20 aresituated fully within the 36×50 framework 100. The left transfer zone 35is in this example of size 7×6 storage cells 122 and the port accessvehicles 3 for transporting storage containers 106 between the transferzone 35 and the port zone 26 are (as indicated with double arrows in Xand Y directions) configured with wheel assembly/drive system 18comprising a first set of wheels 18 a enabling movements in the Xdirection and a second set of wheels 18 b enabling movements in the Ydirection. Even if the port access vehicle 3 are illustrated as singlecell vehicles capable of lifting a single storage container 106, it isto be understood that the port access vehicle 3 with drive system 18 formovements in both X and Y directions can be of any size capable oflifting any number of storage containers.

The right transfer zone 35 shows an example of a 3×40 storage cellsoperated by a single port access vehicle 3 covering 3×2 storage cellsand capable of picking 3×2 storage containers 106 in one pickingoperation.

Again, with reference to FIGS. 12-14, when a storage container 106stored in the storage grid 104 is to be accessed, one of the storagecontainer vehicles 101 is instructed to retrieve the target storagecontainer 106 from its position in the storage grid 104 and to transportthe target storage container 104 to an access station 32 where it can beaccess from outside of the storage grid 104 or transferred out of thestorage grid 104. This operation involves moving the storage containervehicle 101 to the grid cell 122 above the storage column 105 in whichthe target storage container 106 is positioned and retrieving thestorage container 106 from the storage column 105 using the storagecontainer vehicle's 101 lifting device (not shown). This step involvesusing the lifting device to lift the storage container 106 from thestorage column 105 through the grid opening 115 of the grid cell 122 andinto the storage space of the vehicle 101.

If the target storage container 106 is located deep within a stack 107,i.e. with one or a plurality of other storage containers positionedabove the target storage container 106, the operation also involvestemporarily moving the above-positioned storage containers prior tolifting the target storage container 106 from the storage column 105.This step may be performed with the same storage container vehicle 101that is subsequently used for transporting the target storage container101 to the access station 32, or with one or a plurality of othercooperating storage container vehicles 101. Alternatively, or inaddition, the automated storage and retrieval system 1 may have vehiclesspecifically dedicated to the task of temporarily removing storagecontainers from a storage column 105. Once the target storage container106 has been removed from the storage column 105, the temporarilyremoved storage containers can be repositioned into the original storagecolumn 105. However, the removed storage containers may alternatively berelocated to other storage columns.

Once the target storage container 106 has been brought into the storagespace of the storage container vehicle 101, the vehicle 101 transportsthe storage container 106 to the transfer zone 35 where it is unloadedinto or on one of the storage columns 105. Each transfer zone 35comprises transfer columns with length and width marked 36 and 37 inFIGS. 12-14, respectively, and is arranged to temporarily hold storagecontainers 106 when in transit between the storage zone 25 and the portzones 26. Since the number of storage columns 105 within a transfer zone35 is larger than the number of available port columns 19-21, thelikelihood of a container handling vehicle 101 not finding a vacantstorage cell to deliver a storage container is low.

The port access vehicles 3 are operated on the track system 108 and havein the examples shown in FIGS. 12-14 a purpose to transfer storagecontainers 106 between the transfer zone 35 and the port zones 26. Whilethe port access vehicles 3 are performing drop-off and pick up betweenthe transfer zones 35 and the port zones 26, the storage containervehicles 101 may continue to transport storage containers 106 betweenthe storage zone 25 and the transfer zones 35.

When the port access vehicle 3 has brought the target storage container106 in the port zone 26, the picking device 4 of the vehicle 3 moves thecontainer 106 above one of the port columns 19-21, for example adedicated exit port column 19. The container 106 is then lowered intothe chosen port column 19-21 and positioned on a conveyor or containerlift (not shown) which transports the container 106 to the accessstation 32.

Once accessed at the access station 32, the target storage container 106is transferred back into the grid 104 to once again be stored in thestorage column 105 in the storage zone 25.

In the transfer zone 35 the storage containers 106 are advantageouslystored on top of the track system 108 and/or in the uppermost layer ofthe grid 104, i.e. in the layer identified as Z=0 and Z=1, respectively.This will minimize the depth the picking device 4 of the port accessvehicle 3 need to reach when dropping of and picking up storagecontainers 106 from the transfer zone 35, thereby allowing for rapidturnaround of the storage containers temporarily stored therein.

In order to allow the storage containers 106 to be temporarily storedonto the track system 108 (Z=0) and/or in the uppermost layer (Z=1) inthe transfer zone 35, each storage columns within the transfer zone 35may comprise stopping devices (not shown), e.g. clamps attached to theupright members 102 surrounding each transfer zone column, therebypreventing the storage container 106 from being lowered into thetransfer zone column 36,37 beyond level Z=0 or Z=1. Of course, theclamps can be attached to the upright members deeper down the transferzone columns, thus allowing the storage containers 106 to be temporarilystored at deeper levels. The desired depth of the storage containers 106may also be achieved by filling the transfer zone columns with other,preferably void, storage containers. The storage container 106 to bestored is then placed on top of this stack.

The examples above have been describing systems using two types ofvehicles 101,3, one storage container vehicle 101 for transportingstorage containers 106 between a storage zone 25 and a transfer zone 35and one port access vehicle 3 for transporting storage containers 106between the transfer zone 35 and a port zone 26. However, the pivot armequipped port access vehicles 3 could also be used as regular storagecontainer vehicles, in particular if the vehicle 3 includes two set ofwheels 18 a,18 b enabling movement in both X direction and Y direction,and more in particular if this two directional vehicle is configuredsuch that storage containers 106 may be picked up from at least twoperpendicular, lateral sides of the vehicle, for example all fourlateral sides.

For monitoring and controlling the automated storage and retrievalsystem 1 so that a desired storage container 106 can be delivered to thedesired location at the desired time without the vehicles 10,3 collidingwith each other, the automated storage and retrieval system 1 comprisesa control system (not shown), which typically is computerized andcomprises a database for monitoring and controlling e.g. the location ofthe respective storage containers 106 within the storage grid 104, thecontent of each storage container 106 and the movement of the vehicles101,3.

The vehicles 101,3 typically communicates with the control system viawireless communication means, e.g. via a WLAN operating under an IEEE802.11 (WiFi) standard and/or via a mobile telecommunication technologysuch as 4G or higher.

Each vehicle 101,3 comprises a battery (not shown) which provides powerto onboard equipment, including motorized wheels, lifting motor andonboard control and communications systems.

In the preceding description, various aspects of an automated storageand retrieval system, a vehicle and a method according to the inventionhave been described with reference to the illustrative embodiment.However, this description is not intended to be construed in a limitingsense. Various modifications and variations of the illustrativeembodiment, as well as other embodiments of the system, the vehicle andthe method which are apparent to persons skilled in the art, are deemedto lie within the scope of the present invention as defined by thefollowing claims.

REFERENCE NUMERALS

-   1 Storage and retrieval system-   3 Vehicle/port access vehicle/second vehicle-   4 Container picking device-   5 Longitudinal pivot arm-   5′ First longitudinal pivot arm-   5″ Second longitudinal pivot arm-   5 a First end of the longitudinal pivot arm 5-   5 b Second, distal end of the longitudinal pivot arm 5-   5 c Pivot arm motor-   5 d Pivot arm shaft-   6 Attachment device/lifting unit-   13 Gripping device/engaging device/clips-   16 Storage container lift mechanism-   17 Steering pins/guiding pins-   18 Wheel assembly of port access vehicle 3/drive system-   18 a First set of wheels, first direction-   18 b Second set of wheels, second direction-   19 First port column/first port-   20 Second port column/second port-   21 Third port column/third port-   22 Lifting plate-   25 Grid storage zone-   26 Port zone-   30 Vehicle body of port access vehicle 3-   32 Access station-   35 Transfer zone-   36 Left transfer zone columns-   37 Mid transfer zone columns-   38 Right transfer zone columns-   40 Lifting motor for lowering/raising of lifting plate 22-   100 Framework structure-   101 Storage container vehicle/first vehicle-   101 a Vehicle body of the storage container vehicle 101-   101 b Drive means in first direction (X)-   101 c Drive means in second direction (Y)-   102 Upright members of framework structure-   103 Horizontal members of framework structure-   104 Storage grid/three dimensional grid-   105 Storage column-   106 Storage container-   106′ Particular position of storage container-   107 Stack-   108 Rail system/track system-   110 Parallel tracks in first direction (X)-   110 a First track of neighboring tracks 110-   110 b Second track of neighboring tracks 110-   111 Parallel tracks in second direction (Y)-   111 a First track of neighboring tracks 111-   111 b Second track of neighboring tracks 111-   112 Grid column-   115 Grid opening-   122 Footprint/grid cell/storage cell-   X First direction-   Y Second direction-   P Horizontal plane-   PP Pivot point-   RA Rotational axis of pivot arm

1. An automated storage and retrieval system comprising: a track systemcomprising a first set of parallel tracks arranged in a horizontal planeand extending in a first direction, and a second set of parallel tracksarranged in the horizontal plane and extending in a second directionwhich is orthogonal to the first direction, which first and second setsof tracks form a grid pattern in the horizontal plane comprising aplurality of adjacent grid cells, each comprising a grid opening definedby a pair of neighboring tracks of the first set of tracks and a pair ofneighboring tracks of the second set of tracks; a plurality of stacks ofstorage containers arranged in storage columns located beneath the tracksystem, wherein each storage column is located vertically below a gridopening; a vehicle for lifting and moving storage containers stacked inthe stacks, each vehicle being configured to move on the track systemabove the storage columns, each vehicle comprising a vehicle body and awheel assembly connected to the vehicle body, the wheel assembly beingconfigured to guide the vehicle along the track system in at least oneof the first direction and the second direction, wherein the vehiclefurther comprises: a container picking device for releasably attachingto a storage container comprising a pivot arm comprising a first endpivotally connected to the vehicle body at a pivot point, wherein thecontainer picking device, by means of a pivoting motion of the pivot armabout the pivot point, is movable between: a first, lifting positionenabling the container picking device to lift at least one storagecontainer from a position beyond the horizontal extent of the vehiclebody; and a second, transport position enabling the container pickingdevice to hold the at least one storage container at least partly insidethe horizontal extent of the vehicle body.
 2. The system according toclaim 1, wherein the container picking device is configured such thatthe pivotal movement of the pivot arm is restricted to a vertical planeoriented in the first direction.
 3. The system according to claim 1 or2, wherein the container picking device further comprises an attachmentdevice pivotally connected to the pivot arm, the attachment device beingconfigured to allow releasable attachment to the at least one storagecontainer.
 4. The system according to claim 3, wherein the attachmentdevice further comprises an attachment body pivotally connected to thepivot arm and an engagement device connected to the attachment body, forreleasably engaging the at least one storage container.
 5. The systemaccording to claim 3, wherein the attachment device has a maximumhorizontal extent covering at least the horizontal extent of a storagecontainer to be picked.
 6. The system according to claim 3, wherein theattachment device further comprises an attachment body pivotallyconnected to the pivot arm, wherein the attachment body has a maximumhorizontal extent covering at least the horizontal extent of a firststorage container and a second storage container when the first andsecond storage containers are arranged adjacent to each other in thefirst direction or the second direction and a gripping device forreleasably gripping at least the first and second storage containers. 7.The system according to claim 1, wherein the container picking devicecomprises a first pivot arm pivotally connected to a first side of thevehicle body aligned in the first direction and a second pivot armpivotally connected to a second side of the vehicle body aligned in thefirst direction.
 8. The system according to claim 7, wherein the firstand second pivot arms are pivotally connected to respective side wallsof the attachment body aligned in the first direction.
 9. The systemaccording to claim 1, wherein the container picking device comprises twomutually parallel first pivot arms pivotally connected to a first sidewall of the vehicle body aligned in the first direction and two mutuallyparallel second pivot arms pivotally connected to a second side wall ofthe vehicle body aligned in the first direction.
 10. The systemaccording to claim 1, wherein a footprint of the vehicle defined as anextent of the vehicle in the first direction and the second direction,is equal to, or less than, the horizontal extent of a grid cell of theunderlying track system.
 11. The system according to claim 1 wherein afootprint of the vehicle defined as an extent of the vehicle in thefirst direction and the second direction, is equal to, or near equal to,the horizontal extent of a grid cell of the underlying track systemtimes an integer of two or more.
 12. The system according to claim 1,wherein the wheel assembly comprises a first set of wheels or first setof belts for engaging with the first set of tracks to guide movement ofthe vehicle in the first direction.
 13. The system according to claim12, wherein the vehicle body comprises a lower part onto which the wheelassembly is rotatably mounted and an upper part located above the wheelassembly, wherein the upper part is inclined inwards along the firstdirection.
 14. The system according to claim 12, wherein the vehiclebody comprises a lower part onto which the wheel assembly is rotatablymounted and an upper part located above the wheel assembly, wherein thepivot point is located at the lower part of the vehicle body, in betweentwo wheels of the first set of wheels.
 15. The system according to claim1, wherein the container picking device further comprises an attachmentdevice configured to allow releasable attachment to at least one storagecontainer, the attachment device comprising an attachment body pivotallyconnected to the pivot arm, a storage container lift mechanism connectedto the attachment body, the storage container lift mechanism beingconfigured to raise and lower the at least one storage container from aposition on or within a grid column to a position fully above the tracksystem and a gripping device arranged on the lower end of the storagecontainer lift mechanism, the gripping device being configured toreleasably grip the at least one storage container.
 16. The systemaccording to claim 1, wherein the wheel assembly comprises a first setof wheels for engaging with the first set of tracks to guide movement ofthe vehicle in the first direction and a second set of wheels forengaging with the second set of tracks to guide movement of the vehiclein the second direction, wherein at least one of the first set of wheelsand the second set of wheels is vertically displaceable by displacementmeans arranged within the vehicle body.
 17. A vehicle for lifting andmoving storage containers stacked in stacks within an automated storageand retrieval system in accordance with any of claims 1-16, wherein thevehicle is configured to move on the track system above the storagecolumns and comprises a vehicle body and a wheel assembly rotatablyconnected to the vehicle body, the wheel assembly being configured toguide the vehicle along the track system in at least one of the firstdirection and the second direction, wherein the vehicles comprises: acontainer picking device for releasably attaching to a storage containercomprising a pivot arm comprising a first end pivotally connected to thevehicle body at pivot point, wherein the container picking device, bymeans of a pivoting motion of the pivoting arm about the pivot point, ismovable between: a first, lifting position enabling the containerpicking device to lift at least one storage container from a positionoutside the horizontal extent of the vehicle body; and a second,transport position enabling the container picking device to hold the atleast one storage container at least partly inside the horizontal extentof the vehicle body.
 18. A method of operating an automated storage andretrieval system comprising: a three-dimensional grid comprising aplurality of storage columns in which storage containers are stacked oneon top of another in vertical stacks, and a port zone which comprises atleast one port allowing transfer of storage containers out of and/orinto the grid; a plurality of first vehicles which are operatedlaterally on the grid for retrieving one or more storage containersfrom, and storing one or more storage containers in, the storagecolumns, and for transporting the storage containers laterally acrossthe grid; which method comprises the steps of: arranging, in the grid, atransfer zone comprising a plurality of transfer columns for temporarilystoring storage containers when in transit between the storage columnsand the at least one port; utilizing the first vehicles to transport thestorage containers between the storage columns and the transfer columns;and utilizing a plurality of second vehicles which are operated on thegrid to transport the storage containers between the transfer columnsand the at least one port, wherein each of the plurality of secondvehicles comprises: a vehicle body, a wheel assembly connected to thevehicle body, the wheel assembly being configured to guide the secondvehicle along the track system in at least one of the first directionand the second direction, a container picking device for releasablyattaching to a storage container within the transfer zone comprising apivot arm comprising a first end pivotally connected to the vehicle bodyat pivot point, wherein the container picking device, by means of apivoting motion of the pivoting arm about the pivot point, is movablebetween: a first, lifting position enabling the container picking deviceto lift at least one first storage container from a position outside thehorizontal extent of the vehicle body; and a second, transport positionenabling the container picking device to hold the at least one storagecontainer at least partly inside the horizontal extent of the vehiclebody.
 19. The method in accordance with claim 18, wherein the automatedstorage and retrieval system is in accordance with any one of claims1-16.